A long-delayed GFCI requirement is set to hit outdoor HVAC equipment in September — unless it’s delayed again

The HVAC industry has enjoyed a key exception to the National Electrical Code (NEC) for the past two code cycles. But that exception is about to expire. 

Catch up quick: Before 2020, GFCI protection was not required for outdoor condenser connections. But in the 2020 NEC, the National Fire Protection Association (NFPA) — which publishes the code — included a GFCI protection requirement for outdoor air conditioners and heat pumps.

• “Problems surfaced almost immediately,” Wes Davis, director of technical services at ACCA, told Homepros in a statement, as homeowners and contractors began reporting GFCI breakers tripping when ACs ran, “due to incompatibility with the equipment.”
• However, in August 2022, following an appeal led by ACCA and AHRI and backed by the National Association of Home Builders, the NFPA exempted outdoor HVAC equipment from the requirement until September 1, 2026 — an exemption that carried into the 2023 edition. (A new NEC edition is published every three years.)

What’s happening: As the deadline approaches, trade groups including ACCA, AHRI, and the National Association of Home Builders plan to submit an emergency Tentative Interim Amendment (TIA) to the NFPA, seeking to extend the expiration date by three years to September 1, 2029.

Zoom out: “When the exception was approved, the electrical industry committed on the record… to have special high-frequency (HF) GFCI devices commercially available by September 1, 2026,” ACCA manager of codes and standards David Bixby wrote in late June.

• “These devices were widely presented as a technical solution to HVAC nuisance tripping caused by inverter-driven compressors, ECM motors, and other power-electronics-heavy components now common in modern HVAC equipment,” he added. 

Yes, but: “As of early 2026, that promise does not appear to be materializing,” Bixby noted, as HF GFCIs suitable for outdoor HVAC applications aren’t broadly available, “nor have they been vetted at scale in real-world residential installations.”

• “Requiring contractors to install protection that does not yet reliably coexist with listed HVAC equipment exposes them to callbacks, downtime, and liability, without delivering corresponding safety benefits,” he added. 

The NFPA didn’t return a request for comment. 

Of note: Roughly 22 states have independently exempted outdoor HVAC equipment from the GFCI requirement until September 1, 2026, or have deleted the requirement outright, according to ACCA, which didn’t specify the breakdown. 

• Those states fall within the 40 that, per the NFPA, have adopted the 2020 or 2023 NEC as of March 1, 2026 — across all 40, excluding those that deleted the requirement outright, the requirement is set to take effect on September 1. 

What’s next: While no timeline is available, “After the TIA is submitted, the NFPA will screen the submission and then, if accepted, will publish it and make it available for comment and input,” an ACCA representative told Homepros.